Book/Report

FZJ-2016-06963

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Wärmekapazitäten und Phasenanalyse der supraleitenden Verbindungen $"Mo_{6+y_o}$ Se$_{8}$" und "$Gd_{x_o}$ $Mo_{6+y_o}$ Se$_{8}$"

Nerz, K.-P. (Corresponding author)FZJ*

1979
Kernforschungsanlage Jülich GmbH Zentralbibliothek, Verlag Jülich

Please use a persistent id in citations: http://hdl.handle.net/2128/13066

Report No.: Juel-Spez-0030

Abstract: High precision heat capacity measurements were performed on a high quality sample of Mo$_{6}$Se$_{8}$. The values obtained for the Sommerfeld-constant $\gamma$, density of states N($E_{F}$) and entropy S$_{e}$(T$_{c}$) of the electronic system are a factor 1.5 to 2 larger than have been published earlier by other groups. The differences are attributed to the lower concentration of impurity phases in our sample. Our sample of Mo$_{6}$Se$_{8}$ shows a discontinuity in the electronic heat capacity at Tc with a relative height (C$_{es}$-C$_{en}$)/C$_{en}$ which is a factor 1.6 larger compared to an ideal BCS-superconductor. The energy gap in the excitation spectrum of the superconductor Mo$-{6}$Se$_{8}$ is a factor 1.4 wider than for an ideal BCS-superconductor in the observed temperature regime. Our data for the electronic heat capacity of the superconducting phase Mo$_{6}$Se$_{8}$ are ingood agreement with the calculated values corresponding to the "Strong coupling" -model of Padamsee et al.. For the characteristic quantity of the electron-phonon interaction, $\lambda$, a value of 0.8 was calculated. All these results support the conclusion that Mo$_{6}$Se$_{8}$ behaves like a superconductor with a strong electron-phonon interaction. In addition heat capacity measurements have been made for samples of the ternary Chevrel-phase compounds "$Gd_{x_o}$ Mo$_{6+y_o}$ Se$_{8}$" which were prepared by a variety of methods. A quantitative analysis of impurity phases has been made from the heat capacity data.

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Contributing Institute(s):

1. Publikationen vor 2000 (PRE-2000 ; Retrocat)

Research Program(s):

1. 899 - ohne Topic (POF3-899) (POF3-899)

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